Titanium steel and the process of manufacturing the same



50 ganese and 0,5% of chromium.

Patented Dec. 29, 1931 UNITED. STATES PATENT OFFICE TITANIUM srEEr. AND THE rRocEss or manur'ncmme THE smE no Drawing. Application filed January 9,1929, Serial No. 381,388, and in Germany October 25, 1927.

This invention relates to improvements in titanium steel and the process of manufacturing the same. U. S. Patent 1,546,176,

July 14, 1925, describes titanium steels and processes of manufacturing the same, which titanium steels are free of carbon? It is now found that similar titanium steels can be manufactured which contain comparatively small amounts of carbon and silicon, and

that steels thus manufactured have a uniform structure, and that all the components of the iron are contained in the steel in a state of solid solution.

It has further been discovered that the property of a'small amount of titanium of about 02% increasing the strength of the steel is even more conspicuous in steels containing a slight amount of carbon than "in steels which are freeof carbon. For example. the strength of a steel containing about 0,1%- of carbon and from about 0.5% to 0.8% of silicon is increased by an addition of about 02% of titanium from 54 kilogrammes to 82 kilogrammes per square millimeter;

In order to obtain the combination of the titanium and carbon in the form of the titanium carbides in solid solution in the steels. the ratio of carbon to titanium in the steel should not exceed approximately. 5:4, and

v the .contentsof carbon and titanium should not exceed about 1% and 0,8% respectivelv. Under such. conditions the steels are still primarily titanium and not carbon steels. They still retain auniform texture and all the constituents are contained in the solid solution condition. In practice the actual contents of carbon and'titanium will preferably not exceed about 0,2% and 0,44% re-' spectively. v

It is also found that the strength of the titanium steel containing a slight amount of carbon can be considerably increased by adding slight amounts of manganese and chr0- mium. For example, the strength of the steel referred to in the first-named example is further increased to 100 kilogrammes per square millimeter by adding 0,5% of man- In all the said steels is about 80% of the strength.

Notwithstanding its high strength the steel can be readily worked, and it has a high expansion and contraction. Further, the'steel is distinguished by a high degree of resistance to wear. The steel can be manufactured by the processes described in the aforesaid pat ent, which patent relates to the manufacture .ofiron-titanium alloys which are free of carbon, the processes being modified only by adding so much carbon, manganese and chromium to the baths as is necessary for obtaining the desired final composition of the baths. But I may also proceed-from the manufacture of the steel on the hearth on'which an iron bath is refined down to a content of 0,1% of carbon and deom'dized by. means of ferromanganese, ferrochromium or ferromanganesechromium-silicides which are nearly free of carbon, being preferably added during the tapping of the metal and preferably in liquid form. In

a modification I may proceed from an overrefined bath of iron which is nearly free of carbon, the said bath being deoxidized by means of ferromangariese, ferrochromiumor ferromanganesechromium-silicides, containing so much carbon that the deoxidized' bath contains about 0,1% of carbon. To the said bath ferrotitanium which is freeof carthe limit bf elasticity 4 ferrotitanium free of carbon bon is added preferably in a liquid state. In

another modification I proceed from an overerty of increasing the'strength, though their influence is less conspicuousfascompared to that of the metals manganese and chromium.-

-refined iron bath which is nearly free of car- 5 iron, about 0,1% of carbon,

Such additionsare boron, zirconium, tungsten, molybdenum, vanadium, and uranium.

Iclaim: 1. The herein described steel containing about 0,270 of titanium, and about 0,5% of silicon. 2. The herein described steel containin iron, about 0,1% of carbon, about 0,2% of titanium, about 0,5% of silicon, about 0,5% of manganese, and about 0,5% of chromium. In testimony whereof I hereunto aflix my signature. WALTHER MATHESIUS. 

